How Are Black Holes Discovered???????????????????????????????????????????????????????????????????????????????????????????????????
Black Holes were originally theorized by J. Robert Oppenheimer (The lead scientist of the Manhattan project*) and H. Snyder when they were working with Einstein's theory of relativity. Einstein himself did not believe in their existence. Keep in mind that just because something is physically possible doesn't mean that it exists. It is perfectly possible that at one time there were creatures that, through a chemical reaction, were able to breath fire. However, we have no logical proof that they did exist and so assume they didn't. This is a logical argument, so scientists set out to prove the existence of black holes by finding one. Trouble is, by definition, a black hole doesn't release anything at all so it shouldn't have a signature of any kind.
Yet black holes do emit a signature of some kind. In a binary system, a solar system consisting of two stars, there the main star, and another star, sometimes a neutron star or a black hole. The black hole sucks up matter from the main star, forming a disk around the blackhole. This disk of matter is accelerated to extremely fast speeds, forcing the matter to heat up and causing the matter to release large amounts of x-rays, and sometimes gamma rays. X-rays and gamma rays are rays with extremely small crest lengths; gamma rays having the smallest. To tell the difference, in binary systems, between neutron stars and blackholes, there are a few main characteristics to look at. Neutron stars usually exist with 3 solar masses or fewer. Anything with a greater solar mass in a binary system is a black hole.
The relevance of this is that these gamma rays and x-rays are the signature scientists look for. Another way is to simply find a location in the universe that emits no light surrounded by objects going toward it and then suddenly disappearing. You can imagine why that would work.
But what about blackholes that don't exist in binary systems?????????????????????
Another place where black holes exist are in the centers of galaxies. Galaxies are large objects with billions of stars that orbit the galaxy's nucleus or center. In the case of galaxy's, black holes exist in their largest form, super massive black holes. Have you ever seen a picture of the Milky Way?
At the center, in that bright light, is a super massive black hole. The light is created by the large numbers of stars and other objects orbiting (or doomed to enter) the black Hole. Its what everything else in the Galaxy orbits around. Without that black hole, our galaxy would either not exist or be much smaller. The pull of the gravity of the black hole is so strong, it can hold even our star, despite how far away it is. It takes us 200 million years to rotate around the center! To find out more on different types of blackholes, and how they were discovered, visit these websites!
How Are Black Holes Discovered???????????????????????????????????????????????????????????????????????????????????????????????????
Black Holes were originally theorized by J. Robert Oppenheimer (The lead scientist of the Manhattan project*) and H. Snyder when they were working with Einstein's theory of relativity. Einstein himself did not believe in their existence. Keep in mind that just because something is physically possible doesn't mean that it exists. It is perfectly possible that at one time there were creatures that, through a chemical reaction, were able to breath fire. However, we have no logical proof that they did exist and so assume they didn't. This is a logical argument, so scientists set out to prove the existence of black holes by finding one. Trouble is, by definition, a black hole doesn't release anything at all so it shouldn't have a signature of any kind.
Yet black holes do emit a signature of some kind. In a binary system, a solar system consisting of two stars, there the main star, and another star, sometimes a neutron star or a black hole. The black hole sucks up matter from the main star, forming a disk around the blackhole. This disk of matter is accelerated to extremely fast speeds, forcing the matter to heat up and causing the matter to release large amounts of x-rays, and sometimes gamma rays. X-rays and gamma rays are rays with extremely small crest lengths; gamma rays having the smallest. To tell the difference, in binary systems, between neutron stars and blackholes, there are a few main characteristics to look at. Neutron stars usually exist with 3 solar masses or fewer. Anything with a greater solar mass in a binary system is a black hole.
The relevance of this is that these gamma rays and x-rays are the signature scientists look for. Another way is to simply find a location in the universe that emits no light surrounded by objects going toward it and then suddenly disappearing. You can imagine why that would work.
But what about blackholes that don't exist in binary systems?????????????????????
Another place where black holes exist are in the centers of galaxies. Galaxies are large objects with billions of stars that orbit the galaxy's nucleus or center. In the case of galaxy's, black holes exist in their largest form, super massive black holes. Have you ever seen a picture of the Milky Way?
At the center, in that bright light, is a super massive black hole. The light is created by the large numbers of stars and other objects orbiting (or doomed to enter) the black Hole. Its what everything else in the Galaxy orbits around. Without that black hole, our galaxy would either not exist or be much smaller. The pull of the gravity of the black hole is so strong, it can hold even our star, despite how far away it is. It takes us 200 million years to rotate around the center! To find out more on different types of blackholes, and how they were discovered, visit these websites!
http://library.thinkquest.org/25715/discovery/galaxies.htm
http://library.thinkquest.org/25715/discovery/middleweight.htm
*The project sponsored by the US government that created the nuclear bomb
"Einstein's Theory of Relativity." Yahoo! GeoCities: Get a free web site with easy-to-use site building tools. 16 Feb. 2009 <http://www.geocities.com/CapeCanaveral/7997/einstein.html>.
"Event Horizon: Discovering Black Holes in Binary Systems." Oracle ThinkQuest Library. 16 Feb. 2009 <http://library.thinkquest.org/25715/ discovery/binary.htm>.
"Event Horizon: Discovering Black Holes in Centers of Galaxies." Oracle ThinkQuest Library. 16 Feb. 2009 <http://library.thinkquest.org/25715/discovery/galaxies.htm>.
Week 3 created by: Dylan Devenyi (Skutner) and someone else.
I had a really cool picture right here, but Mrs. Klos made me get rid of it. This is the URL:http://iasos.com/audioclp/StairwayToHeaven-D-4d.jpg